Preheat oven to 400 degrees. In a large bowl, whisk together the flour, baking powder and salt. Cut up COLD butter into small chunks; add to flour mixture. Use a pastry blender and cut the butter into the flour until butter has been reduced to the size of small peas. You can also do this in a food processor if desired. Add sugar; stir to combine. Set aside.

In separate bowl, add heavy whipping cream, eggs and vanilla extract. Whisk together until blended. Set aside.

Add frozen blackberries to flour mixture. Toss gently to lightly coat the berries with flour. Pour whipping cream/egg mixture into flour mixture. Stir gently to mix. Please note that frozen berries will begin to thaw very fast, so do this step quickly, but gently. Your dough will be fairly sticky.

Once mixed, place the dough onto a lightly floured work surface. Knead the dough VERY LIGHTLY 3-4 times so dough comes together in a ball. Shape dough into an 8 inch circle using your hands. The dough should be about 1½ inches high. Cut into 8 wedges with a sharp knife or pizza cutter.

Place the scones onto an ungreased baking sheet in a circle, leaving a little space between each wedge. If desired, sprinkle tops with sugar (optional). Bake in preheated 400 degree oven for 20-22 minutes, or until tops are light golden brown in color and they are "set" in the middle. When finished baking, let scones cool on baking sheet for several minutes, then transfer to a wire rack to finish cooling. Serve at room temperature... and enjoy!